VHO Question

[Murminator]

How may watts before it's called VHO? Garfs website he is calling 40W VHO. I always thought it was higher like 110W.

[Delphinus]

VHO technically refers to the .. um .. I'm sure to get this wrong but I'm going to make a stab at it anyhow... the amperage pushed through the bulbs. NO lamps (whether 20W, 40W or whatever, depending on the length), use one amperage (plus whatever voltage to make it 20W or 40W), then HO uses an amperage higher than that, and then VHO uses an amperage even higher than that. 48" VHO lamps are 110W, 24" VHO's are 75W.

So anyhow, there's no such thing as a "40W VHO". More likely he means he's running 40W lamps overdriven using a 110W ballast. Which you can do (assuming an electronic ballast is used), you will get some increased lumen output of the fluorescent, at the cost of (presumably) shortened useful lamp life.

[Skimmerking]

Yes Tony again hit the answer right on the button . ITs 40W BULB ran on a VHO ballast like a icecap.660 or a 440 with a Normal bulb 40 that is .


mike

[Murminator]

Thanks guys for clearing that up :mrgreen:

[danny zubot]

Sorry to hijack, has anyone ever heard of overdriving T-5's the same way?

[Skimmerking]

Danny I'm doing it with the t-5 on m 660 icecap. If you go to the members tanks my 170 is lite by 2x 48" t-5"s 12K go take a look.

its very bright

[Delphinus]

I don't see why it couldn't be done. I was going to try running 2 T5's on my WH7 which pumps out 220W so at 54W each for the HO T5's that would be basically exactly 2x overdriven.

But, I haven't gotten around to buying the lamps, endcaps and reflectors just yet.

[Skimmerking]

the bulbs are 54W and they are driven at 85 W

mike

[4ptbuck]

VHO= Very High Output
HO= High Output
NO= Normal Output

As you go up the chain, more amps are pushed through each tube.
Typically bulbs are rated for NO, HO, or VHO.
You can overdrive the bulb by using a different ballast to push more amps through.

For a standard 48" bulb

VHO=very high output 115watts
HO=high output 60watts
NO=normal 40watts

So if you hook up a 48" HO ballast to a 48" NO bulb, you are driving it 1.5X
48" VHO to 48" NO bulb 2.875 times.

Of course the possibilities are endless, but as you overdrive, things run hotter, and don't last as long.

[StirCrazy]

I don't see why it couldn't be done. I was going to try running 2 T5's on my WH7 which pumps out 220W

No, it doesn't pump out 220 Watt, it will provide stable current up to 220W. so depending on how you hook it up if they are HO T5's to start with then they take two wires each to run normal so the only way to over drive them would be to switch them to a series set up or run one ballast for each.

Also remember you only get a percentage increase and it isn't 100% I only got a 15% increase overdriving my HO and only a 38% increase overdriving NO by 4X.

I also think a T5 would be more prone to break down by over driving than VHO or HO or NO T-12's as the smaller diameter with increased light output means more intensity which also mean more heat and less area to dissipate it.

Steve

[Delphinus]

Umm.. Ok. The words are kinda English but put into that order, they make no sense to me. I'm sure to someone who really likes to geek out on this sort of thing it makes perfect sense but to me it might as well be "The banana tennis map under the purple." Although I think I understood as much as "don't bother trying it".

[StirCrazy]

Umm.. Ok. The words are kinda English but put into that order, they make no sense to me. I'm sure to someone who really likes to geek out on this sort of thing it makes perfect sense but to me it might as well be "The banana tennis map under the purple." Although I think I understood as much as "don't bother trying it".

weird some one took the 5's and 4's out of my post... Brad must be back:mrgreen:

Steve